Abrasively machined gas turbine components

Abstract

A method of making a gas turbine engine component includes providing a nickel based alloy workpiece and removing material from the workpiece surface using an abrasive machining operation to form an axisymmetric surface on the workpiece using the abrasive machining operation. The workpiece axisymmetric surface and workpiece interior portion have uniform hardness and micro structure following the removing operation.

What is claimed is: 
     
         1 . A method of machining a nickel based gas turbine component, comprising:
 providing a nickel based alloy workpiece;   removing material from the workpiece using an abrasive machining process to form an axisymmetric surface on the workpiece using the abrasive machining process, wherein the axisymmetric surface and interior portion of the workpiece have uniform hardness and microstructure following the removing operation.   
     
     
         2 . A method as recited in  claim 1 , wherein the removing step includes forming an unpeened and unpolished ground axisymmetric surface. 
     
     
         3 . A method as recited in  claim 1 , wherein the removing step includes inducing residual stress in the axisymmetric surface and the subsurface portion that is substantially the same as residual stress in the interior portion. 
     
     
         4 . A method as recited in  claim 1 , wherein the removing step includes inducing residual tensile stress in the subsurface portion that is the substantially the same as tensile stress within the interior portion. 
     
     
         5 . A method as recited in  claim 1 , wherein the removing step includes inducing residual compressive stress in the subsurface portion that is substantially the same as compressive stress within the interior portion. 
     
     
         6 . A method as recited in  claim 1 , where the workpiece is a forging. 
     
     
         7 . A method as recited in  claim 1 , wherein the workpiece is a powder metallurgy preform. 
     
     
         8 . A method as recited in  claim 1 , wherein the abrasive machining process includes an grinding process. 
     
     
         9 . A method as recited in  claim 1 , wherein removing operation is a roughing operation. 
     
     
         10 . A method as recited in  claim 9 , wherein the roughing operation removes between about between 20% and 80% of the workpiece by volume or weight. 
     
     
         11 . A method as recited in  claim 1 , wherein the removing operation is a roughing and a finishing operation. 
     
     
         12 . A method for forming a gas turbine disk, comprising:
 providing a nickel based workpiece;   removing a first portion of workpiece material in a roughing operation using an abrasive machining process, wherein the abrasive machining process removes between about 20% and about 80% of the workpiece by volume or weight; and   removing a second portion of workpiece material in a finishing operation using the abrasive machining process, wherein the each removing operation forms an axisymmetric surface, wherein the axisymmetric surface, subsurface, and interior portion of the workpiece have substantially uniform hardness and microstructure following the removing operation.   
     
     
         13 . A method as recited in  claim 12 , wherein the abrasive machining process is a grinding process. 
     
     
         14 . A method as recited in  claim 12 , wherein residual stress in axisymmetric surface, subsurface portion, and interior portion is substantially the same following the removing operation. 
     
     
         15 . A method as recited in  claim 12 , further including peening the axisymmetric surface following the finishing operation. 
     
     
         16 . A gas turbine engine disk, comprising:
 a nickel based alloy body, defining:
 a ground axisymmetric surface; 
 a subsurface portion adjacent to and axially inward of the axisymmetric surface; and 
 an interior portion adjacent to and axially inward of the subsurface portion, wherein the axisymmetric surface, subsurface portion, and interior portion have substantially uniform hardness and microstructure. 
   
     
     
         17 . A disk as recited in  claim 16 , wherein the ground axisymmetric surface is an unpeened and unpolished ground surface. 
     
     
         18 . A disk as recited in  claim 16 , wherein residual stress within the axisymmetric surface, the subsurface portion, and interior portion is substantially the same. 
     
     
         19 . A disk as recited in  claim 16 , wherein residual tensile stress in the subsurface portion is substantially the same as tensile stress within the interior portion. 
     
     
         20 . A disk as recited in  claim 16 , wherein residual compressive stress in the subsurface is substantially the same as compressive stress in the interior portion.